Well, could you first tell how to make a force field? Would make it easier to explain how to shape it.
A force field is a region of space in which an object will experience an applied force, the magnitude and direction of which can be determined from field properties (this is not to say that the only force experienced by the object while within the field will be that due to the field) and certain characteristics of the object. The gravitational field of a mass is a force field. Electric and magnetic fields are force fields. Fluid pressure can be viewed as a force field.
All of the examples that I listed can be shaped, to one degree or another. Gravitational fields can be shaped by changing the distribution of mass in the object or objects creating the field and changing the shape of the mass distribution. Electric and magnetic fields can be shaped by changing the charge or current distribution that creates the field, by changing the shape of the path taken by the current which creates the field, or by changing the shape of the charge distribution. Fluid pressure fields can be shaped by playing with densities, temperatures, and velocities of the fluid in a given region, which will in turn have an effect on the pressure distribution throughout the fluid.
Also, why exactly are we talking about lightsabers and shaping force fields, anyways?
Regarding the power station around a gas giant to make use of the radiation coming off of it: this is rather pointless when there's a significantly better source of radiation which most likely can be made use of at a point more conveniently located close to an inhabitable world, don't you think? If I'm looking to create a power station which works off of absorbing incident radiation, the first place I'm going to turn to is the local star, not the local gas giant. Another thing is that if you're going to use a space station as a power plant, you really need to think about how you're going to get that power from the space station to the point of use. There'd better be a very good economical reason for me to build a power plant around Jupiter if the point of use is on Earth, and it's not going to be that Jupiter is somehow a better location for absorbing radiation. It might be a decent place to put a starship fuel manufacturing plant, especially if some significant portion of the material necessary for manufacturing the fuel can be obtained relatively easily from the gas giant's upper atmosphere or its moons, and it might be a safer (or more acceptable to the populace) location for a large-scale antimatter production facility than something closer to home.
Similarly, any mining prospect is going to have to have an explanation for why it's better to mine a gas giant, which is merely the thing with the most significant gravity well and least hospitable environment, aside from the local star, in the system, as opposed to mining the same resource at some place where it's easier to recover the materials from. Upper atmosphere gas extraction isn't too bad; mining the core of the gas giant, though? Whatever you can find there is going to be cheaper to obtain from just about anywhere else, and if it can't be then there's an enormous economic incentive to come up with a decent way to synthesize whatever it is, because a gas giant has deepest gravity well of anything in the system that isn't a bigger gas giant or the local star, which means it has a higher escape velocity, which means it requires more energy to get things out of it. Beyond that, its interior is an extremely hostile environment, which means that any equipment designed for use there is going to be more expensive than that used for extraction from asteroids and rocky planets/planetoids/moons, and likely has a greater cost for failures, as damage is likely to be crippling and rapidly lead to the destruction of the equipment.
Regarding the species inhabiting the gas giant: I don't really see a point to this. Something which evolves for life on or within a gas giant is unlikely to need anything that comes from a rocky planet, as most likely there are some asteroids or a small moon somewhere which provide more convenient and cheaper access to whatever materials they need, and rocky worlds aren't going to be classed as inhabitable for them any time soon. Similarly, there are far more convenient sources of anything you can find in a gas giant somewhere else in a Sol-like system for species which evolved on rocky worlds to make use of, and unless GCIII includes something like Cloud City from Star Wars, a gas giant really isn't a viable colonization target, either (its moons might be, but anything which inhabits the gas giant is not going to be competing for habitation space with something colonizing its moons, and may even consider this beneficial, as it would no longer need to concern itself with extracting resources from the inhabited moon, as trading with the new residents would most likely be more convenient). Thus, at least the way I see it, species which inhabit gas giants natively have little reason to compete with species that inhabit rocky worlds; at worst, it'd be who gets to collect taxes on the inhabitants, not who gets to live where.